1. Field of Invention
The present invention relates to a chalkboard, for example a blackboard, eraser cleaner system including a closeable container in which is preferably contained an electrically driven beater for the cleaning of or chalk dust removal from the eraser.
2. Prior Art
In schools and the like, it is common, traditional practice to have black/greenboards or other chalkboards for use by the teachers in the teaching process. For removal of the chalk-written information on the board, hand manipulated erasers have been provided for many years to remove the chalk from the boards. This results of course in the erasers in due course becoming saturated with the chalk dust, causing the need to clean the erasers for further use.
In the past, it has been common practice for the students to clean the erasers by hitting them together or against a wall to cause the chalk dust to be propelled into the air and thus removed from the erasers. This obviously has been a very messy, time-consuming and unsatisfactory approach.
There have been a number of attempts in the prior art to attempt to provide more sophisticated tools for the cleaning process.
Various prior art patents which disclose or describe chalk board eraser cleaners are listed below:
______________________________________ Patentee(s) Pat. No. Issue Date ______________________________________ T. Adams 906,983 Dec. 15, 1908 G. A. Marshall 1,540,996 June 9, 1925 J. F. Palmer 1,757,545 May 6, 1930 J. C. Mather 1,985,939 Jan. 1, 1935 F. L. Hennefer 2,163,788 June 27, 1939 F. M. Schaefer 2,306,911 Dec. 29, 1942 F. L. Hennefer 2,323,908 July 13, 1943 J. M. Di Persio 2,874,398 Feb. 24, 1959 F. L. Hennefer 2,896,234 July 28, 1959 G. J. Dalton 3,395,413 Aug. 6, 1968 ______________________________________
Some of the prior art devices have utilized non-motorized approaches, such as for example the Dalton patent (U.S. Pat. No. 3,395,413) in which the eraser is hand manipulated back-and-forth over an opening in contact with a weighted scrubber-beater which swings back-and-forth as the eraser is moved; and the Di Persio patent (U.S. Pat. No. 2,874,398) which uses a box in which the eraser is placed on a spring mounted, relatively rigid screen platform, with the box being shaken vigorously to cause the eraser to be shaken and knocked about in the box with the dust falling through the screened platform.
A manually, hand cranked version of a eraser cleaner is shown in the Adams patent (U.S. Pat. No. 906,983), which provides a completely closeable box having a door through which the eraser is positioned on a rigid trough or shelf and is held in position by a spring wire rod as the eraser is cleaned by the beating action of cleaner fingers. A bottom door is included for removal of the collected chalk dust.
However, most of the prior art devices utilize electrically driven motorized cleaners in which the eraser being cleaned is hand-held over an open slot beneath which is positioned a rotatable beater which, by impact against the bottom of the eraser held in the slot, cleans it; note the patents to Palmer (U.S. Pat. No. 1,757,545), Mather (U.S. Pat. No. 1,985,939), and Schaefer (U.S. Pat. No. 2,306,911). A similar approach is shown in the series of three Hennefer patents (U.S. Pat. Nos. 2,163,788; 2,323,908; and 2,896,234) except that reciprocating beaters are used rather than rotatable beaters.
In the Marshall patent (U.S. Pat. No. 1,540,996) a relatively large rotatable beater is rotated centrally within a cylindrical housing in which for example twelve erasers are fixedly positioned spaced along the inner periphery of the housing by channels plates.
However, all of these prior art devices have various problems and drawbacks associated with them.
Those which have open areas in which the erasers are positioned allow the dust to be expelled out into the area surrounding the cleaner, potentially dirtying the user of the cleaner. Additionally, these types, as well as others of the prior art, require that the user be in constant attendance at the cleaner in order to hold the eraser.
On the other hand, those that provide a completely closed container for the eraser and its cleaning elements during use, have mounted the eraser on a rigid shelf or in fixed positions, which accordingly required very precise positioning of the beater and did not allow for wearing of the beater after substantial use. Thus, after the beater had become worn from use, its cleaning action started to diminish. Additionally, in contrast to this prior art, allowing the eraser to have some movement during the cleaning operation enhances the effectiveness of the cleaning by its own kinetic motion and action as well as by positioning the eraser at different points with respect to the direct point of impact from the moveable beater.
The present invention overcomes all of the foregoing prior art problems, as well as others, and does so with a relatively straight-forward, compact, reliable, simple, inexpensive and portable device.
3. Summary Discussion of Invention
The present invention in its preferred embodiment provides a completely, closeable container or housing for the eraser and the cleaning elements during use and supports the eraser during use by flexible, for example, mesh netting, means positioned adjacent to a moveable, for example, rotatable, beater.
Additionally, for greatly simplified and ease of use, the eraser is inserted into the closeable container through a side, slot-like door, which is used to push the eraser into the container into engagement with a spring-biased electrical contact switch, causing the beater drive means to be activated. Upon completion of the cleaning operation, the door is merely opened, allowing the eraser to at least initially be ejected by the spring bias, breaking the electrical contact, and allowing easy removal of the eraser from the device.
At the bottom of the container, there is preferably provided a removeable drawer, which is positioned below the beater and collects the chalk dust during use for later removal and disposal of the chalk dust in bulk.